Portion of a shoe sole



FIG. 1 is a left side elevational view of a portion of a shoe sole showing my new design;

FIG. 2 is a front elevational view thereof; and,

FIG. 3 is a rear elevational view thereof.

The broken line showing of a shoe sole and of a shoe upper in the Figures is environmental only and forms no part of the claimed design. 

The ornamental design for a portion of a shoe sole, as shown and described. 